network: beef up ipv6 RA support considerably

This reworks sd-ndisc and networkd substantially to support IPv6 RA much more
comprehensively. Since the API is extended quite a bit networkd has been ported
over too, and the patch is not as straight-forward as one could wish. The
rework includes:

- Support for DNSSL, RDNSS and RA routing options in sd-ndisc and networkd. Two
  new configuration options have been added to networkd to make this
  configurable.

- sd-ndisc now exposes an sd_ndisc_router object that encapsulates a full RA
  message, and has direct, friendly acessor functions for the singleton RA
  properties, as well as an iterative interface to iterate through known and
  unsupported options. The router object may either be retrieved from the wire,
  or generated from raw data. In many ways the sd-ndisc API now matches the
  sd-lldp API, except that no implicit database of seen data is kept. (Note
  that sd-ndisc actually had a half-written, but unused implementaiton of such
  a store, which is removed now.)

- sd-ndisc will now collect the reception timestamps of RA, which is useful to
  make sd_ndisc_router fully descriptive of what it covers.

Fixes: #1079

1 files changed, 156 insertions, 7 deletions

diff --git a/src/libsystemd-network/test-ndisc-rs.c b/src/libsystemd-network/test-ndisc-rs.c
index 4817c968ac..d9669488be 100644
--- a/src/libsystemd-network/test-ndisc-rs.c
+++ b/src/libsystemd-network/test-ndisc-rs.c
@@ -18,11 +18,15 @@
 ***/
 
 #include <netinet/icmp6.h>
+#include <arpa/inet.h>
 
 #include "sd-ndisc.h"
 
+#include "alloc-util.h"
+#include "hexdecoct.h"
 #include "icmp6-util.h"
 #include "socket-util.h"
+#include "strv.h"
 
 static struct ether_addr mac_addr = {
         .ether_addr_octet = {'A', 'B', 'C', '1', '2', '3'}
@@ -35,6 +39,144 @@ static int test_fd[2];
 typedef int (*send_ra_t)(uint8_t flags);
 static send_ra_t send_ra_function;
 
+static void router_dump(sd_ndisc_router *rt) {
+        struct in6_addr addr;
+        char buf[FORMAT_TIMESTAMP_MAX];
+        uint8_t hop_limit;
+        uint64_t t, flags;
+        uint32_t mtu;
+        uint16_t lifetime;
+        unsigned preference;
+        int r;
+
+        assert_se(rt);
+
+        log_info("--");
+        assert_se(sd_ndisc_router_get_address(rt, &addr) == -ENODATA);
+
+        assert_se(sd_ndisc_router_get_timestamp(rt, CLOCK_REALTIME, &t) >= 0);
+        log_info("Timestamp: %s", format_timestamp(buf, sizeof(buf), t));
+
+        assert_se(sd_ndisc_router_get_timestamp(rt, CLOCK_MONOTONIC, &t) >= 0);
+        log_info("Monotonic: %" PRIu64, t);
+
+        if (sd_ndisc_router_get_hop_limit(rt, &hop_limit) < 0)
+                log_info("No hop limit set");
+        else
+                log_info("Hop limit: %u", hop_limit);
+
+        assert_se(sd_ndisc_router_get_flags(rt, &flags) >= 0);
+        log_info("Flags: <%s|%s>",
+                 flags & ND_RA_FLAG_OTHER ? "OTHER" : "",
+                 flags & ND_RA_FLAG_MANAGED ? "MANAGED" : "");
+
+        assert_se(sd_ndisc_router_get_preference(rt, &preference) >= 0);
+        log_info("Preference: %s",
+                 preference == SD_NDISC_PREFERENCE_LOW ? "low" :
+                 preference == SD_NDISC_PREFERENCE_HIGH ? "high" : "medium");
+
+        assert_se(sd_ndisc_router_get_lifetime(rt, &lifetime) >= 0);
+        log_info("Lifetime: %" PRIu16, lifetime);
+
+        if (sd_ndisc_router_get_mtu(rt, &mtu) < 0)
+                log_info("No MTU set");
+        else
+                log_info("MTU: %" PRIu32, mtu);
+
+        r = sd_ndisc_router_option_rewind(rt);
+        for (;;) {
+                uint8_t type;
+
+                assert_se(r >= 0);
+
+                if (r == 0)
+                        break;
+
+                assert_se(sd_ndisc_router_option_get_type(rt, &type) >= 0);
+
+                log_info(">> Option %u", type);
+
+                switch (type) {
+
+                case SD_NDISC_OPTION_SOURCE_LL_ADDRESS:
+                case SD_NDISC_OPTION_TARGET_LL_ADDRESS: {
+                        _cleanup_free_ char *c = NULL;
+                        const void *p;
+                        size_t n;
+
+                        assert_se(sd_ndisc_router_option_get_raw(rt, &p, &n) >= 0);
+                        assert_se(n > 2);
+                        assert_se(c = hexmem((uint8_t*) p + 2, n - 2));
+
+                        log_info("Address: %s", c);
+                        break;
+                }
+
+                case SD_NDISC_OPTION_PREFIX_INFORMATION: {
+                        uint32_t lifetime_valid, lifetime_preferred;
+                        unsigned prefix_len;
+                        uint8_t pfl;
+                        struct in6_addr a;
+                        char buff[INET6_ADDRSTRLEN];
+
+                        assert_se(sd_ndisc_router_prefix_get_valid_lifetime(rt, &lifetime_valid) >= 0);
+                        log_info("Valid Lifetime: %" PRIu32, lifetime_valid);
+
+                        assert_se(sd_ndisc_router_prefix_get_preferred_lifetime(rt, &lifetime_preferred) >= 0);
+                        log_info("Preferred Lifetime: %" PRIu32, lifetime_preferred);
+
+                        assert_se(sd_ndisc_router_prefix_get_flags(rt, &pfl) >= 0);
+                        log_info("Flags: <%s|%s>",
+                                 pfl & ND_OPT_PI_FLAG_ONLINK ? "ONLINK" : "",
+                                 pfl & ND_OPT_PI_FLAG_AUTO ? "AUTO" : "");
+
+                        assert_se(sd_ndisc_router_prefix_get_prefixlen(rt, &prefix_len) >= 0);
+                        log_info("Prefix Length: %u", prefix_len);
+
+                        assert_se(sd_ndisc_router_prefix_get_address(rt, &a) >= 0);
+                        log_info("Prefix: %s", inet_ntop(AF_INET6, &a, buff, sizeof(buff)));
+
+                        break;
+                }
+
+                case SD_NDISC_OPTION_RDNSS: {
+                        const struct in6_addr *a;
+                        uint32_t lt;
+                        int n, i;
+
+                        n = sd_ndisc_router_rdnss_get_addresses(rt, &a);
+                        assert_se(n > 0);
+
+                        for (i = 0; i < n; i++) {
+                                char buff[INET6_ADDRSTRLEN];
+                                log_info("DNS: %s", inet_ntop(AF_INET6, a + i, buff, sizeof(buff)));
+                        }
+
+                        assert_se(sd_ndisc_router_rdnss_get_lifetime(rt, &lt) >= 0);
+                        log_info("Lifetime: %" PRIu32, lt);
+                        break;
+                }
+
+                case SD_NDISC_OPTION_DNSSL: {
+                        _cleanup_strv_free_ char **l = NULL;
+                        uint32_t lt;
+                        int n, i;
+
+                        n = sd_ndisc_router_dnssl_get_domains(rt, &l);
+                        assert_se(n > 0);
+
+                        for (i = 0; i < n; i++)
+                                log_info("Domain: %s", l[i]);
+
+                        assert_se(sd_ndisc_router_dnssl_get_lifetime(rt, &lt) >= 0);
+                        log_info("Lifetime: %" PRIu32, lt);
+                        break;
+                }}
+
+                r = sd_ndisc_router_option_next(rt);
+        }
+}
+
 static int test_rs_hangcheck(sd_event_source *s, uint64_t usec,
                              void *userdata) {
         assert_se(false);
@@ -83,32 +225,39 @@ int icmp6_send_router_solicitation(int s, const struct ether_addr *ether_addr) {
         return send_ra_function(0);
 }
 
-static void test_rs_done(sd_ndisc *nd, uint8_t flags, const struct in6_addr *gateway, unsigned lifetime, int pref, void *userdata) {
+static void test_callback(sd_ndisc *nd, sd_ndisc_event event, sd_ndisc_router *rt, void *userdata) {
         sd_event *e = userdata;
         static unsigned idx = 0;
-        uint8_t flags_array[] = {
+        uint64_t flags_array[] = {
                 0,
                 0,
                 0,
                 ND_RA_FLAG_OTHER,
                 ND_RA_FLAG_MANAGED
         };
+        uint64_t flags;
         uint32_t mtu;
 
         assert_se(nd);
 
+        if (event != SD_NDISC_EVENT_ROUTER)
+                return;
+
+        router_dump(rt);
+
+        assert_se(sd_ndisc_router_get_flags(rt, &flags) >= 0);
         assert_se(flags == flags_array[idx]);
         idx++;
 
         if (verbose)
-                printf("  got event 0x%02x\n", flags);
+                printf("  got event 0x%02" PRIx64 "\n", flags);
 
         if (idx < ELEMENTSOF(flags_array)) {
                 send_ra(flags_array[idx]);
                 return;
         }
 
-        assert_se(sd_ndisc_get_mtu(nd, &mtu) == -ENOMSG);
+        assert_se(sd_ndisc_get_mtu(nd, &mtu) == -ENODATA);
 
         sd_event_exit(e, 0);
 }
@@ -132,17 +281,17 @@ static void test_rs(void) {
 
         assert_se(sd_ndisc_set_ifindex(nd, 42) >= 0);
         assert_se(sd_ndisc_set_mac(nd, &mac_addr) >= 0);
-        assert_se(sd_ndisc_set_callback(nd, test_rs_done, NULL, NULL, NULL, e) >= 0);
+        assert_se(sd_ndisc_set_callback(nd, test_callback, e) >= 0);
 
         assert_se(sd_event_add_time(e, &test_hangcheck, clock_boottime_or_monotonic(),
                                  time_now + 2 *USEC_PER_SEC, 0,
                                  test_rs_hangcheck, NULL) >= 0);
 
         assert_se(sd_ndisc_stop(nd) >= 0);
-        assert_se(sd_ndisc_router_discovery_start(nd) >= 0);
+        assert_se(sd_ndisc_start(nd) >= 0);
         assert_se(sd_ndisc_stop(nd) >= 0);
 
-        assert_se(sd_ndisc_router_discovery_start(nd) >= 0);
+        assert_se(sd_ndisc_start(nd) >= 0);
 
         sd_event_loop(e);